simonds



(No Model.)

l 4 Sheets--Sheet 1.

G. F. SIMONDS.

(moss GUT SAW.

Patented Deo. 26,1?827.

N. PETERS. Phulo-lllhngmphnr. Washmgon. D. C.

(No Model.)

G. F. SIMONDS.

4 Sheets-Sheet 2.

4 Sheets--Sheet 3.

(No Model.)

G. P. SIMONDS.

(moss GUT SAW.

/f/,Patented 1390.26, 1882.

faja/1, of j Jl( w CCQJ; (234% 7 fw@ /4 62mm 4 Sheets-Sheet 4.

l(No Model.)

G. F. SIMONDS.

GROSS GUT SAW No. 269,728. Patented Dec.26, 1882.

@yer/i073' NTTED STATES PATENT 'OEETCE cRosscuT-SAW.

SPECIFICATION forming part of Letters Patent No. 269,728, dated December26, 1882.

Application filed October 27, 1882. (No model.)

.tion of a thisthack crosscut-saw that sha-lient a i1 even kerfthroughout its length, that shall not bind in the cut, and that shall berelatively thickened and strengthened toward the ends, whereby morelumber can be cut and with less labor than as heretofore.

lily invention consists in a crosscutsaw of substantially uniformthickness throughout the length of its curved cutting-edge, and ofgrailually-diminishing thickness in the direction of its width fromcuttingedge to back.

What is known as a crosscutsaw is usually a long thin plate ot' steelgradually narrowing in width from its middle toward each end, and

-having the edge in which the cutting-teeth are formed curvilinear ingeneral contour; AAs such saws are intended for use in cuttinglogs andheavy timbers, provision needs to be made lor preventing theirbinding byreason of the closure ofthe walls of the kerf upon them, especially whenthe cut has been nearly completed and there is not left enough uncutmaterial to keep the timber from sagging at that place. To compensatefor such tendency to be bound in the kerfis the principal object ofgrinding the saw-plate, by which it is made to taper in thickness fromthe cuttingedge to .the opposite edge or"back, so called, and is thusenabled to be run without binding unless fthe sagging ofthe timberproceeds so far asto incline the walls ofthe kert' to each other at Vanangle greater than that of the taper given to the saw-plate itself. Themechanical means commonly/employed for performing this grind-A ing hasbeen primarily an ordinary grind- `stone and a presser-bar set acrossits acting face at an inclination corresponding to the de- 1n otherwords,

plane at right angles tothe direction ofthe ,".tween lthe grindstone andthe presser-bar the saw-plate is passed, with opposite sides prelmotionof the grinding-surface at that place.

Through the angular space thus formed bel sented alternately to thegrinding-surface at each successive passage, and the` back edge alwaystoward the converging lines of the angie. In this way the portions ofthesaw-plate adjacent to the back are first operated upon, and as theybecome reduced in thickness the back ofthe saw is made to enter fartherin between the presser-bar and the grinder, until the whole plate isbrought toa taperin the direction of its width.

The method of grinding crosscnt-saws heretofore practiced has been tomove them in a rectilinear path. from end to end straight across theline of maximum action of the grinder. or substantially perpendicular tothe plane which is common to that line and the presser-bar. By thismeans each plate was ground tapering in thickness transversely fromcutting-edge to back at right angles to the straight path of itsmovement upon the grinder; but while suoli mode ot' treatment made thesaw-plate better able to escape binding by the inclination of the wallsof the kerf it produced defects which created other serious diflicultiesin the way ot' practical use, for itwill be perceived that as the sawwas moved bodily endwise in a rectilinear path through the angular spacebetween the in clined presser-bar and the surface ofthe grindstone thelines of uniform thickness in the tapered plate would rnn straight fromend to end, and thus the cutting-edge of the sawplate, by reason ofitscurvature and the consequent passage of its various portions throughspaces of different widths between the presserbar and the grinder, wasmade to vary in thickness proportionately t0 its departure from astraight line; or, in other words, such curvilinearcutting-edgegraduallyincreased in thickness from each end to the middle, and thisinequality remained even after setting the teeth of the saw, because itwas not feasible to increase the degree ot' their inclination totheplane of the saw-plate by as much as they decreased in thickness, norconversely. Hence every such crosscut.- saw would cut a wider -kerfalong its middle than toward either end, and as a practical consequencewhenever it was worked with a long stroke one of two undesirable resultswould follow-namely, either the teeth of the middle portion would bindin the kert' already made by the teeth of the portions located nearerthe ends or would not run IOO at all in the narrower kert, but wouldride over it and be occupied in performing the useless labor ot'enlarging the same by cutting down its walls. Furthermore, thecomparative thinness ofthe saw-plate at and near its ends rendered itliable to kink or snap there in the at temp's of the workman to force itby pushing.

Before proceeding to describe my improved method of' grinding and thenew productresulting therefrom, it will aid to a better understanding ofthe subject to further consider the cotiditions under which the oldmethod ofgrinding has taken place, and some ot which are still presentin the practice ofthe tiew method.

Thus far the positions and movements ofthe saw have been referred to thepresser-bar and grinder; and it is evideiittliatin practice sometiiechanical means mtist be employed for perfoi ming the ottices of thepresser-bar in holding the saw against the grinder at the properinclination. Forexample.crosscut-saws have been ground between twogrindstones actitig simultaneously on opposite sides ot' the plate, andin such case the grinding-surfaces, where they come into action, areinclined to each other at an angle corresponding to that ofthe taper tobe given to the saw transversely, and they reciprocally,perform cach forthe other the lunctions ot' a presser-bar; but for the purposes of'deiining the relationship of the sawplate to the. grinding-surface thepresser-bar or its equivalent may be left out ot' account.

It will be readily understood that whether the grinding ot' the sawproceeds alternately on opposite sides, as with one griiidstoiie, orsimultaneously, as with two grindstones, the transversely-tapering plateis substantially bisymmetiical with reference toa geometrical planepassing through the median lines of its edges. or, in other words, thatsuch a platte divides it edgewise into two plate-s substatitially equaland similar each to each. .For convenietice of description we shallrefer to this geometrical plane which symmetrically divides theplateedgewiseas the plane ofthe saw-plate. Further economy ot'description may be gained by denoting the line ot' maximum action ot'thegrinder as simply the grinding-line, which, in the case ot' a machineemploying a prt=sserbar, as already explained, would be located at theintersection with the grinding surface of a plane perpendicular thereto,and at right angles to the direction of motion thereof, passing throughthe presserbar longitudinally and centrally-that is to say, throughwhat, for brevity, may be termed the axisof thepresser-bar; atid in thecase of two grinders co-operating upon opposite sides ot' the saw-platethe grinding-line of each would he located at the intersection ot' thesame plane with their respective grinding-surfaces, perpendicularthereto and at right anples to the direction of motion thereof. Itslionld be understood, also, that the tertn grinding-line as here usedis intended to signify not merely so much of it as is co-extensive withthe actual dimension ofthe grinding-surface along the line oti itsmaximum action, but also the further geometrical extension thereof inthe saine direction indefinitely. [n case of a griudstone thecylindrical periphery ot' which acts upon the saw-plate tangenti-ally,the grinding-line is parallel to the axis of the stone, and thc planeperpendicular to the grinding-surface. and at right angles to thedirection of motion thereof', whose intersection therewith is coincidentwith the grinding-line, also passes through the axis 0f the griiidstone.It may liappeti that the periphery ot' the grinder is slightly convex,so as to grind the transverse taper of' the sawplate a little concave,in which case the actual grinding-line would be somewhat curved; butt'or the pui-poses of definition this variation is immaterial, since,whether theangnlar space between the grindstone and the presser-bar orits equivalent be bounded by converging curves or converging stra-ightlines, the sawplate, when in proper position therein for grinding, willalways have its platte inclined to the grinding-line and its back towardthe apex ofthe angle ot' inclination.

Instead of moving the saw-plate to the action ot' the grindstone in arectilinear pat-h, I give it such movement as to cause every part ot itscurved cutting-edge, throughout the entire length thereof, to passsuccessively through the plane which is common to the axis of thepresser -bar and the grinding line at substantially the same pointduring any given passage, so that the lines ot' uniform thickness in thetapered plate are curves running substatitiallv parallel to the generalcurvature ot' the cutting-edge, because by 'keeping the cutting-edge ot'the saw-plate where it passes the grinding-line at the saine distancefrom the apex ot the angle of inclination of the presser bar all otherportions which pass through any given cotistant part of the angularspace between the presser-bar and the grinder, and which areconsequently reduced to unit'orm thickness, will necessarily be actedupon at the same distance from the point at which the cutting-edge ismaintained, and will therefore be located in a curve which conforms tothe curvature ot' the cutting-edge. In accomplishing this movement otthe saw-plate, it will be made to describe a curvilinear path varying inform according to the direction taken by its ends while its cutting-edgepasses the grinding-line at a consta-nt point. Thus, for example, it maybe given a movement which is the resultant of simultaneous lateral atidlongitudinal movements similar in character to that ot' which one memberofa parallel ruler is capable, the outetedge corresponding to the backot' the saw-plate, and in such instance its successive positions will beparallel to one another, while as a whole it will describe a path thecurvature of which is the reverse ot' that ot its cutting-edge; but lprefer, as a more convenient way ot' grinding my improved saw, to movethe entire saw-plate in a curvilinear path substantially parallel to thegeneral curv- IOO IOS

etarras.

ature of its cutting-edge; and to this end Il although it is obviousthat the requisite moven'ients ofthe saw-plate between the grinder andthe presser-bar might be giveir by hand,

especially with the aid ofa gage or stop against which to keep thecutting-edge ofthe saw-plate to insure its passage across thegrinding-line at a tixed point. l am thus enabled not only to giveuniform thickness to the cutting-edge ofthe saw throughout its entirelength, but also to make the plate of the utmost strength and stiffnessat the ends consistent with their narrower width. To be sure, thedirection of the taper in thickness of the saw-plate from cutting-edgeto back will vary somewhat, according to the specitic way in which mymethod of grinding is practiced-that is to say, when the parallelism ot"the successive positions of the saw-plate is maintained, as in the tirstexainplegiven, the taper in thickness will be in directions at rightangles to the chord joining the ends of the curve ofthe cutting-edge;and

when thejentire saw-plate is moved in a curvilinear path parallel to thecurvature of the cutting-edge, as in the second example given, thetaperin thickness will be in direct-ions diametrically across the curvesalong which the grinding` takes place, or, in other words, in adirection at any given point of the curvature of the cutting-edgeperpendicular `to the tangent ofthe curve at that point; but these dit'-ferences are immaterial so far as the practical uses of the saw areconcerned. All this will more readily appear from the drawings annexedto this specitication, and forming part thereof, wherein- Figure 1represents in cross-section taken through the grinding-lineperpendicular to the direction ot motion ot' the grinding-surface thegrindstoiie and presser-bar ot' a grindingmachine with a saw-platebetween them. B is the grindstone, C the presser-bar, and x the saw. zis the apex of the angle between the presser-bar .and the grinder, andyz the line which ls coincident willi the platte of the saw-plate. y

Fig. 2 represents the extreme and middle positions of a saw withrelation to the presserbarand grinder when ground bytheold method bymoving` in a rectilinear patti.

Fig. 3 represents the extreme and middlepositions of a saw with relationto the presserbar and grinder when ground according to my new method bya movement similar to that of one member ot' a parallel ruler.

Fig. 4 represents the extreme and middle positionsofa saw with relationto the presserbarand grinder when ground accordingl to my new method iuthe way which I prefer.

In each of the Figs. 2, 3, and 4 the broken line w fw', ruiminglengthwise of the presserbar C, indicates the position ot' thegrindingline.

Fig. 5 represents the flat side of a crosscntsaw, with broken linesindicating the direction in which the grinding proceeded thereon by theold method.

Fig. 6 represents the same side of a crosscut saw, with broken linesindicating the direction in which the grinding has proceeded thereon bymy new method.

Fig. 7 shows in cross-section the relative dimensions of a crosscnt-sawof ordinary size, taken at its middle, the saine being 14 wire gage vinthickness at the cutting-edge and 18 wire gage at the back.

Fig. shows the relative thickness of such a crosscut-saw at the endswhen ground by the old method, the same being,r 16 wire gage -at lthecutting-edge and 18 wire gage at the back.

Fig. 9 shows the relative thickness of such a size of crosscut saw atthe ends when ground by my new method, the saine being 14 wire gage atthe cutting-edge and 16 wire gage at the back. The wire-gage thicknessesof the two saws in various parts of ltheir length are further indicatedin Figs. 5 and 6, respectively.

Fig. l() representsa plan view of a grindingmachine embracingimprovements which I have invented for antoiiiatically putting intopractice my new method of grinding crosscutsaws but for thebettershowing of these parts certain mechanism for adjusting and holdingthe presser-bar is'omitted in this view.

Fig. 1l is an end elevation of the machine, viewed when looking towardthe broadside of the grindstone.

Fig. 12 is a side elevation viewed when looking toward the edge of thegrindstone and nearest the teed-rolls between which the sawplate istirst introduced.

Like parts ot' the machine in the different figures are designated bythe same letters.v

A indicates the upright supports for the feeding and guiding mechanism.B is the grindstone; U, the presser-bar, which holds the saw-plate downupon the stone during the grinding operation; D, the driving-pulley forthe feeding-rolls, a b b c c', a train of gears intern'iediate betweenthe driving-pulley and the feeding-rolls; d d', shafts of upperfeedingrolls; e e', shafts ot'lower feeding-rolls; fgj"g,

gears upon the shafts of the upper and lower l teeding-rolls,respectively, by which they are driven together; h i, forward pair offeedingrol'ls, which tirst act upon the saw-plate; h t7", rearward pairof feeding-rolls.

E is a yoke-shaped frame containing the bearings for the shaftsot' thefeeding-rolls, and F is a frame of similar shape, in which thedriving-pulley l), the intermediate gears, a b

b. c c', and the rear ends of the upper feeding- The two frames E rollshafts, d d', are hung. F are supported upon bars G G', to which theyare fastened by set-screws. The bars GG slide in bearings l7c l It l',which are supported by the uprights A, so that by means ot theleverH,'wnich has its fulcrum at m in the stationary bar I, and is connectedto the yoke E by a pin, a, working in aI slot, thc two yoke'- frames EF, with the feeding-rolls h t' h t" and all their driving-gear, may bemoved toward and from the grindstone at the will of the operator.

o o are links which hold together the projecting ends of the shafts ofeach pair ot' upper and lower feeding rolls to prevent them fromspringing apa-rt unduly when the saw-plate is passed between them. l

J J J are guides against which the cuttingedge ot' the saw-plate istriade to bear in its progress through the machine, and which cooperatewith the feeding-rolls to give to thesaw-plateacurvilinearmovementsubstantially conforming to the generalcurvature of the cutting-edge.

K is a brace connecting the upper ends ot' the upright portions of theframe of the machine, and snpportingthe bearings ofa shaft-,19, on whichis a hand-wheel, q, for regulating the position of the presser-bar C.This shaftp has upon it two bevel-gears, r t", which mesh into otherbevel-gears, s s', respectively, on the upper ends of screw-rods t t.These latter turn in nuts u u,attached to slides ti fu', which carry thepressenbar C between them. The end of this presser-bar which is towardthe end of the l machine opposite to that containing the driving-pulleyis jointed to its slide in such manner as to enable it to be set at aninclination with the grinding-surface corresponding to the desired taperof the thickness of the saw-plate.

In machines of this kind heretofore used for grinding -crosscut-saws thetwo sets of feeding-rolls have been parallel to each other andsubstantially perpendicular to the plane ofthe grindstone, so that theyhave always fed the saw-plate over the grimling-surface in a rectilinear path. On the otherhand,1 have so organized the machine that thetwo sets of feed-Y -ingerollcrs have their respective axes inclined to.each other, so that by their conjoint action upon the sawplate they willmove it in a curvilinear path substantially conformingr to the generalcurvature of the cutting-edge of the saw. To accomplish this result inthe best manner, the axes of each set of feeding-rollers should beperpendicular to the tangent ofthe rurve ofthe path of movement to begiven to the saw at the point where such curve passes between therollers, so that, for instance, in case thecurve of the path of movementwere an arc of a circle, a plane passing through both axes of eitherpair of feeding-rollers would cut such arc in the direction of a radiusthereto at the point of intersection.

lt will be readily understood that in order to have a set -otfeeding-rollers on each sideof the line where the grinder acts they mustnecessarily be placed far enough apart to enable the lower roller ot'each pair to lie below the plane which is tangent to the grindstoneatits grinding-line, and hence while either end of the saw-plate ispassing` across the space inter.- vening between the feeding-rollers onopposite sides of the grinding-line there needs to be, in addition tothe single pair ot' feeding-rollers then acting upon the saw-plate, someauxiliary means for insuring' its movementin the re quired curvilinearpath, For this purpose `I have provided the stationary guideshereinhefore'descrihed with surfaces for the cuttingedge if thesaw-plate to-bear against, both in front of the forward pair offeeding-rollers and alsobetween those and the rearward pair,s that whileei ther set offeeding-rollers, acting singly, tends to move the plate ina direction at right angles to its axis, such tendency may be constantlycurbed and the required curvilinear movement produced by keeping thecuttingedge of the saw-plate against the guides. The same result mightbe effected by providing an additional pair of feeding-rollers outsideof each of those shown and described,and having their respective axes inlike manner perpendicular to the tangent of the curve of the path ofmovement to be given to the saw-plate at the point where it passesbetween them; but my invention of the new crosscut-saw herein describedis not limited by the specific character of the mechanism which may beemployed for producing the same, the prime object being to eliminatecertain practical detects consequent upon the old method of grinding instraight lines from end tocnd of the saw-plate; and the advantages ofconstruction begin to be measurably obtained in straight saws as soon asthe grinding takes place along curves which begin to approximate to thecontour of the general curvature of the cutting-edge of the saw-plate,whatever may be the mechani- .cal means employed for effecting suchmodeof operation, so that although in order toinsure complete uniformityin the thickness of the cutting-edge of the saw-plate the direction ofthe grinding should perfectly conform to its curvature, yet the saw willbe substantially made by any form of such curvilinear grind ing asconstitutes a material departure from the old way of straight grinding.

The improvements which I have invented in machinery for grindingcrosscut-saws according to my improved lnethod of grinding, which I haveherein described for the purposes of illustrating my invention hereinclaimed, I reserve as the subject-matter of an application for aseparate patent.

What I claim as my invention is- As a new article of manufacture,acrosscutsaw otsubstantially uniform thicknessthroughout the length ofits curved cutting-edge, and of gradually-diminishing thickness in thedirection ofits width from cutting-edge to back.

v GEORGE F. SIMONDS.

Witnesses:

J oHN SIMoNDs, Gao. P. WARD.

llO

IIS

